a) Field of the Invention
The present invention relates to a timer unit for mechanically controlling the operation times of valves, respectively, which act to switch the condition of fluid passages.
b) Background Art
A toilet bowl equipped with a flushing device is required to store water in its flush tank and also in its cleaning warmed water tank. The amount of water stored in the flush tank differs from the amount of water stored in the cleaning water tank. Tap water supplied from a single tap is guided into the two tanks by controlling the operation times of valves, or the times for which their respective valves are opened, according to the capacities of the tanks. The valves are mounted between the tap and their respective tanks.
An electrical timer unit is incorporated in each valve mechanism mounted in the fluid passage extending from the tap to each tank to control the valve mechanism. A different time is set into each timer unit. In particular, the valve for a flush tank requiring a large amount of water is set up so that it is opened for a long time. The valve for a cleaning warmed water tank requiring a relatively small amount of water is set up so that it is opened for a short time.
In this way, electrical timer units are known which control their respective valves in such a manner that liquid supplied from a single liquid supply port is divided into two dissimilar amounts of liquid discharged from plural delivery ports. All of these electrical timer units are equipped with a control printed board.
Where a valve is opened and closed under the control of an electrical timer unit, the timer fails to operate in the event of a power failure. For example, where valves in a flush toilet are controlled by electrical timer units, supply of water to the tanks is impossible in the event of a power failure. This is a fatal problem with the flush toilet. To make preparations for a power failure, it is necessary to provide a manual valve. However, this makes the appliance large and increases the cost.